Abrading or polishing machine



y 1935. c. JOHNSON ET m.

ABRADING OR POLISHING MACHINE Filed June 29, 1932 2 Sheets-Sheet 1Patented May 28, 1935 h c 2,002,666

. UNITED STATES PATENT OFFICE,

i aooases. V v ABRADING on POLISHING MACHINE, Charles Johnson and CarlLawrence Mattison, t

3 Rockford, Ill., assignors to MattisonxMachine wfork s, Rockford, 111.,a corporation of Illinois a licat on June 29, 1e32, Serial No. 619,836

' 10 Claims. (01. 51-135) One of the objects -of the invention is' tovent buckling or warping of'the sheet due to provide'novel andimprovedmeans for driving the heat generated therein by the abrading theabrading or polishing belt and=for pressing mechanism. I g 7 the beltagainst the work. r The endless abrasive belt I S'is supported upon 5Another object is to provide novel and imtwo idler pulleys l6 which aresuitably jour- 5 proved means for reciprocating the presser naled on themachine frame and the lower or carriage. j I 'activ'e run of this beltruns around rolls on 9. Another object is toproduce a novel machinecarriage I] which is mounted on a horizontal in which the abrading orpolishing operation rail l8 to reciprocate longitudinally of said belt.

10 maybe performed either throughthe medium 'This carriage I1 is,ireciprocated-by means of 10 of the usual endless belt or directly bythe an endless cable I 9, running over a pair of presser roll'whichpresses the \belt against the sheai'es 20 journaled on the machineframe, one work. of whichsheaves is driven alternately in oppo- Afurther object is to provide a presser carsite directions by reversibleelectric motor 2| riage of novel construction by which the posiandsuitable reduction gearing 22. The car- 15 tion of the presser roll maybe varied to accomriage has means to be presently described for modatework of different thicknesses. attaching it to thelower run of saidcable 19.

In the accompanying drawings, Figure 1 is Means is provided forautomatically reversa front eleyation with parts broken away showing theelectric ,inotor 2|, which means in the ing'a -machin'embodying ourinvention. exemplary embodiment herein shown is actu- 20 Fig. 2 is anlevational view illustrating the ated by the movement of the carriagell. A remechanis m' 'for reciprocating the presser car-, versing switch23 mounted on the machine has riage. I a pair of contacts 24 and apivoted switch arm Fig. 3 is a vertical front-to-rear sectional 25 whichcontacts and arm are connected by 25 view through said carriage. wires26 to the reversing fields of the motor 2li' Fig. 4 is a rear elevationof/ the carriage in a manner well known. The switch has a showing amodified form of means for driving Sp 27 a d to t arm 25 acting o holdthe presser roll. the arm in engagement with either one of the Thepresent invention is applicable to a m contacts 24, with the result thatthe motor will 30 chine of the general type disclosed in Patent bedriven in one direction or the other depending No. 1,478,044,issued'December 18, 1923, to Carl 1113011 whi h one Of the contacts thearm en- Lawrence Mattison, but in the present applicaag A r d 8 slidablymounted in h ri tion we have shown only such parts of the 29 O the m hframe has a P Of p machine as are necessary to an understanding tiOnSembracing the Switch arm d t of the invention. I rod also carries a pairof collars 3| which are M It should be understood that the presentadjustable along the rod and are secured thereinvention is susceptibleof embodiment in varoby sui a l m ns s h s s t s w Th ious forms andalternative constructions. and Collars n DOSitiOHtO be engaged by a Pthat the illustration by way of example of one Oh the Carriage l in itsreciprocation Q effect '40 preferred embodiment of the invention is notto alternate longitudinal movement of e od in 40 be taken as anintention to limit the invention Opposite directions and thereby swingthe switch to th present disclosure, The scope of the arm 25 from one ofthe contacts 24 to the other. invention will be pointed out in theappended It w thus be seen that by setting he o lars l ims, 3| atdifferent distances apart, the range of re- The machine comprises a airof pedestals" r i n of th r i m y be v ri d n 45 I0 connected at theirupper ends by a support Controlledupon whi h th iou Operating mecha- Thecarriage comprises two sections, one of nlsms are carried. The pedestalsalso carry wh designated is q pped with a plutracks I! running fromfront to rear upon which rality of rollers 32 to run upon a guide railI8.

60 the work supporting table I3 is mounted. A 'The other section ll ofthe carriage is mounted pair of spaced hold-down rollers I4 are jourforvertical sliding movement upon the first naled in bearings on thepedestals inioverlymentioned section.

ing relation to the work table and act to press The means for connectingthe carriage to the against the work table the piece of work A,reciprocating cable l9 may be of any suitable 65 which may be a sheet ofsteel, and thereby pre-' form, that herein shown comprising an arm 33'(Fig. 3) projecting rearwardly from the carriage section II and havinga finger 34 to engage between a pair of stops or collars 35 fixed on thecable 19.

The lower carriage section [1 is mounted on vertical guideways 36 on theupper section and is held by a vertical screw 31 rotatably mounted inthe lower section and threaded in a lug 38 on the upper section,-whichlug passes through a slot 39 'in the lower section. A collar4ll fixed onthe screw 31 prevents endwise movement of the screw relative to thelower section so that by rotating the screw the lower carriage sectionmay be adjusted vertically by the operator.

In the lower carriage section are mounted a pair of idler rolls 4| and acombined driving and belt pressing roll 42. The lower run of theabrasive belt l5 passes over the top of the two idler rolls and downunderneath the driving and pressing roll 42. The belt is thusflexedsharply out of the plane of the lower run thereof to form arelatively small loop which accomplishes a two-fold purpose in that itinsures driving traction between the presser roll 42 and the belt and itgives the belt a much more efficient cutting action. In passing aroundthese carriage rolls, the belt is sharply flexed in alternately reverseddirections which acts to loosen dust or foreign matter that alwaystendsto pack in between the abrasive grains and which, if not removed, wouldeventually cause the belt to glaze with the result that its cuttingaction is impaired and more heat is generated. As the belt passes aroundthe presser roll 42 the particles of abrasive are spread apart so thattheir cutting edges aremore effectively brought into action along thezone of contact with'the work. has been found that this greatlyincreases the efliciency of the abrading action and also permits wornparticles of abrasive to free themselves and escape from the belt andthereby present fresh sharp particles into cutting engagement with thework. The length of life of the belt is thus increased.

The presser roll 42 is preferably made of or surfaced with a yielding orcushion material which compresses very slightly under the existingpressure to maintain a narrow zone of contact between the belt and thework a little wider thana mere line contact. It has been found thatproviding a contact zone about Y three-eighths of an inch in width givesthe most eflicient cutting action.

The idler rolls 4| are mounted on the carriage in such position that theupper surfaces of said rolls lie substantially in the plane of thelowermostpoints on the periphery of belt supporting pulleys I6 so thatthe tension upon and deflection of the belt in its passage through'thecarriage I! will remain constant in all positions of the carriage in-itsreciprocation.

In prior machines of this type, the abrasive belt hasusually been drivenby one of the pulleys I6. It has been found that driving the belt fromthe presser roll on the carriage greatly reduces the strain on the beltand the liability of danger of its tearing or breaking; also that thequality of the work is improved because the surface of the presser rolldoes not have a tendency to be roughened by the belt and there is lesstendency to vibration or chattering at the point of contact of the beltwith the work than is the case where the belt is driven from one of thepulleys l8.

of the present invention to mount on the carriage power means fordriving the presser roll and, through said roll, the abrasive belt is.The arrangement of this power driving means may be varied to suitrequirements. In the present instance we have shown in Figs. 3 and 4 twoalternative constructions. Referring first to Fig. 3, the presser roll42 is mounted on a shaft is journalled in the carriage and this shaftconstitutes anextension of or is axially alined with and fixed torthearmature shaft of an electric motor 44 which is secured beneath arearwardly projecting portion of the lower carriage section. It will benoted that the presser roll 42 is positioned between'the two hold-downrollers l4 and the electric motor 44 is located rearwardly of the rearone of said hold-down rollers, the shaft with the presser roll 42, andpower is communi-' cated from the motor ;to said presser roll by a belt45 running over sheaves 4B fixed respectively on the armature shaft andthe shaft of said presser roll. By replacing the sheaves 4% with sheavesof relatively different diameters, the speed of the presser roll 42 maybe varied at will.

It will be understood, of course, that suitable connections between themotors 2i and 44 to power lines and suitable controlling switchestherefore are provided. It is not deemed necessary to illustrate thisarrangement herein since it may be of conventional form and constitutesno part of the present invention.

If desired, the abrasive belt may be removed from the machine and anabrasive or polishing sheet fastened about the periphery of the presserroll 42, or instead the presser roll may be removed from the carriageand another roll having abrasive or polishing material on its peripherymay be substituted therefor.

In operation the sheet of material A to be finished is laid upon thework table l3 while the table is in its foremost position. The table isthen pushed rearwardly to carry the sheet beneath the hold-down rollersl4. Either the supporting rails H for the work table or the bearings forthe hold-down rollers H or both may be made vertically adjustable tovary the space between said hold-down rollers and the upper surface ofthe work table for accommodation of work of different thicknesses. Theconstruction of the carriage I! also permits, through manipulation ofthe screw 31, a micrometer adjustment of the height of the presser roll42. To control the range of reciprocation of the carriage .to accordwith the width of the work piece, the operator may adjust the stopcollars 3| on the rod 28 so that the switch 22 will be reversed when thecarriage has traveled a desired distance in either direction. When theproper relationship has been established, the motors 2| and 44 may bestarted and so long as the carriage is coupled to the cable IS thecarriage will be reciprocated along its guide rail, with the abrasivebelt I5 or the abrading or polishing surface of the roll 42, as the casemay be, in contact with the work A. The work table is moved rearwardlyeither by hand or by power as the carriage reciprocates so that everypoint on the sheet. A will be treated. If desired, the arm 33 on thecarriage may be disengaged from the driving cable I! and the position ofthe carriage may be then manually controlled so that the operator maygive further or special treatment to any spots on the work which havenot been finished to the desired degree.

We claim as our invention:

1. A machine of the character described having, in combination, anendless belt to operate on the work, a plurality of idler pulleyssupporting said belt, and means for driving said belt and for pressingthe belt against the work comprising a carriage mounted to reciprocatealong said belt, a power-driven presser roll on said carriagefriotionally engaging and driving said belt and pressing the beltagainst the work, and a pair of idler rolls located at opposite sides ofand close to said presser roll and acting to hold said belt in contactwith said presser roll and to cause alternate reverse flexing of thebelt so as to free foreign matter and to spread the abrasive particlesapart at the zone of en gagement with the work for better cuttingaction.

2. A machine of the character described having, in combination, anendless abrading or polishing belt, a plurality of pulleys supportingsaid belt, and means for driving said belt and for pressing the beltagainst the work comprising a carriage mounted to reciprocate parallelto the active run of the belt, a presser roll mounted on said carriagein driving engagement with the belt and arranged to press the beltagainst the work, a pair of idler rolls mounted on said carriage onopposite sides of and close to said presser roll and holding said beltagainst said presser roll, and a motor mounted on said carriage fordriving said presser roll and thereby driving said belt.

3. A machine of the character described having, in combination, anendless abrading or polishing belt, a carriage mounted to reciprocatealong the active run of said belt, a plurality of rolls mounted on saidcarriage over which rolls said active run ot'the belt passes, one ofsaid rolls acting to press the belt against the work, and power means onsaid carriage for driving the last mentioned roll and thereby drivingsaid belt.

4. A machine of the character described having, in combination, anabrading or polishing belt, means for supporting said belt, and meansfor driving said belt and for pressing the belt against the workcomprising a carriage mounted to reciprocate along the active run ofsaid belt, a pair of idler rolls on said carriage engaging said belt, apresser roll mounted on said carriage between and close to said idlerrolls and engaging said belt to deflect a loop thereof sharply out ofthe plane of the remainder of the active run of the belt for engagementwith the work, and a motor mounted on said carriage for driving saidpresser roll and thereby driving said belt.

5. A machine of the character described comprising, in combination,means for supporting a piece of work, work hold-down means overlyingsaid work supporting means, abrading or polishing means including acarriage mounted to re ciprocate along the work, a presser roll on saidcarriage, and a driving motor on said carriage operatively connected tosaid roll. said roll and said motor being located at opposite sides ofsaid hold-down means.

6. A machine of the character described having, in combination, ahorizontal work table, a pair of hold-down rollers overlying said worktable, abrading or polishing means above said work table including acarriage mounted for horizontal reciprocation parallel to said rollers,a presser roll on said carriage located between said hold-down rollersfor pressing the abrading or polishing means against the work, and adriving motor mounted on said carriage and drivingly connected to saidroll, said motor being located at the outer side of one of said holddownrollers relative to said presser roll.

'7. A machine of the character described having, in combination, anendless belt for operating on the work and having a plain and anabrasive side, a plurality of idler pulleys supporting said belt toprovide a run with a straight portion, a power-driven presser rollfrictionally engaging the plain side of said belt at the straightportion of the run to drive the belt, and a pair of idler rolls locatedat opposite sides of and close to said presser roll and engaging theabrasive side of said belt, said presser roll being offset relative tosaid idler rolls to deflect the belt into engagement with the work andto cause the belt to contact with a substantial portion of the peripheryof said presser roll to insure proper driving traction between thelatter and said belt.

8. A machine of the character described having, in combination, anendless belt for performing a working operation, a carriage mounted forreciprocation along a piece of work and longitudinally of said belt, aplurality of rolls mounted on said carriage over which said belt passes,one of said rolls acting to press a face of said belt against the workto perform a working operation, and power driven means on said carriagedrivingly connected with one of said rolls for driving said belt.

9. A machine of the character described having, in combination anendless abrading or polishing belt, a carriage mounted to reciprocatealong the active run of said belt, a roll mounted on said carriage overwhich the active run of the belt passes and by which the belt is pressedagainst the work, and power means on said carriage for driving the lastmentioned roll and thereby driving said belt.

10. In a machine of the character described, the combination of a framehaving a work supporting face, an endless belt having an active runextending substantially parallel to said face, a pair of hold-downrollers disposed adjacent to said face and located in substantialparallelism, one on each side of said active run, a reciprocatingcarriage mounted for movement longitudinally of said active run, and adriven roll mounted on said carriage and engaging said active run fordriving said belt and for pressing it against the work between saidhold-down g rollers.

CHARLES JOHNSON. CARL LAWRENCE MA'I'I'IBON.

